The present invention relates to an antenna module, especially to a switching circuit and a control method of the antenna module that improves efficiency of the antenna module.
Due to fast development of wireless technology, the function of wireless devices are dramatically improved so that people's lives are more convenient. For example, wireless network devices avoid the problem of general network devices that are restricted by wires. Without antennas, wireless network devices such as access points or client stations can't transmit or receive information. Therefore, antennas play a key role in wireless network devices.
Nowadays the antenna module is disposed with a switching circuit for switching a plurality of antennas arranged thereof and thus providing various modes of use of wireless network devices. The switching circuit includes a plurality of switches coupled between a signal processing unit and antennas. A transmitting signal generated by the signal processing unit passes the switches and then sends to the antenna for transmission. A signal received by the antenna also passes through the switches and arrives at the signal processing unit for reception. A control unit controls on/off of the switches. Thus through the control unit, the antenna of the antenna module intended to use is selected.
However, while switching the antenna of the antenna module, conventional switching circuit can only switch to one antenna so that there are limited modes of use for antenna module. For example, there is an antenna module with four antennas, only four modes of use are provided. Moreover, due to limited gain of each antenna, if only one antenna is used, the maximum effective isotropic radiated power and receive sensitivity are restricted. Thus the performance of wireless network devices is also affected.
Therefore there is a need to provide a switching circuit and a control method of an antenna module with a plurality of modes of use so as to increase gain of the mode for improving efficiency of the antenna module and further enhancing performance of the embedded wireless network devices.